Current lifting surface architectures for jetliners consist of 2 swept torsion boxes (right and left sides) with a central joint at the aircraft centreline. Eventually, a central torsion box is used instead of a central joint depending on the aircraft architecture.
In classic metallic structures, the skins of such torsion boxes were manufactured with a number of riveted foils.
In modern aircraft, thanks to the contribution of composites to parts integration, those skins can be single composite parts from the central joint to the tip. In other words, current state-of-art allows having only 4 full-size skins to produce left and right torsion boxes (2 upper skins and 2 lower ones). A central joint (or central torsion box) is still used to fix both sides to the aircraft fuselage or body.
There are known some proposals of single parts for aircraft lifting surfaces. In this respect US 2003/0098116 A1 discloses a stabilizing element comprising two portions in which the principal directions intersect at a non-singular angle which is manufactured by a continuous lay-up operation on both parts using two lay-up coordinate systems (one for each portion). This proposal seems to be applicable to small sized lifting surfaces (stabilizers for helicopters or sport airplanes for example).
The aircraft industry demand continuously a higher degree of design optimisation of typical airliners' lifting surface architectures (multi-rib or multi-spar) driving to both cost and weight reduction.
The present invention is intended to satisfy this demand.